As a safety measure, the pressure of gas as measured at the outlet of the utility's service pipe to any consumer, or in the case of high pressure system, at the outlet of the utility's service regulator, shall be maintained as uniformly as practicable. It shall not be less than one-half nor more than twice the pressure at which the regulator is set, provided, however, that such limit may be exceeded by 2 p.s.i.g. if the regulator fails.
Okla. Admin. Code § 165:45-7-1